Typewriting machine



Original Filed Dec.

28, 1927 n 2 Sheets-#Sheet 1 mmm S QNW.

INVENTOVR $4M A w WITNESES i f ATTORNEY.

061.13, 1931. F A, HART 1,827,431

TYPEWRITING MACHINE Original Filed Dec. 28, 1927 2 Sheets-Sheet 2 INVENTOR BY m4, 51m/L ATTORNEY Patented Oct. 13, 1931 .UNITED STATES PATENT, oFFlcE FREDERICK A. HART, 0F NEW BRITAIN;

CONNECTICUT, ASSIGNOR TO REMINGTON TYIEWRITER COMPANY, 0F I LION, NEW YORK, A CORPORATION OF NEW YORK TYPEWRITING MACHINE Application led December 28, 1927, Serial No. 242,992. Renewed February 24, 1931.

' My invention yrelates to typewriting machines and it has for its principal object to provide an improved power driven case shift mechanism for such machines, and especially one in which the shifting operation takes place with the quickness desired in a power driven machine, but smoothly and with no objectionable shock and jar.

The mechanism is preferably driven by a continuously rotating power shaft. It com prises a cam or eccentric which lifts. the

platen with an accelerated motion and withf out sudden starting and stopping, and allows the platen to drop back to normal position in a similar way. The follower is however connected with the platen through a toggle joint so designed that said joint approaches a straight positon as the platen is raised, with the vresult that he positive acceleration of the motion of the platen itself during the first part of its upward movement is greater than the negative acceleration during the latter part of its upward movement when the platen is diminishing in-velocity. In other words, the velocity is acquired more abruptly and is diminished more gradually p than it would be if the follower were arranged to communicate its motion directly to the platen. These peculiarities of motion are of course reversed on the return stroke. The cam or eccentric is connected with and disconnected from the continuously rotating part by means of a clutch acting somewhat on the principle ofvan escapement of'such sort that when the case shift key is depressed the clutch is connected up for a half rotation, the parts being arrested at the end of the half rotation, provided the key is held down. When the key is released the clutch is again connected to complete the rotation of the cam. The platen is moved to upper case position during the irst described motion and is returned during the second described motion.

The i specific instance of my invention shown in the drawings is applied to the machine well known commercially as the Remington electric typewriter and only so much of said machine is shown in the drawings as is necessary to illustrate my invention. In

said drawings Fig. 1 .is a front to rear vertical sectional view of the machinewith many parts omitted but showing .my invention.

Fig. 2 is a perspective view of some of the connections from the power mechanism to the platen.

Fig. 3 is a right-hand side view of the unit containing most lof my mechanism, together with some associated parts.

Fig. 4 is a top view of the same.

Fig. 5 is a front to rear vertical sectional view about on the line 5 of Fig. 4'and looking in the direction of the arrow at said line.

Fig.v 6 is a transverse vertical sectional view about on the line 6, 6 of Fig. 3 and looking in the direction of the arrow; that is to say, toward the rear of the machine.

Fig. 7 is a sectional view, partly on the line 7 and partly on the line 7, 7 of Fig. 3 and looking toward the rear.

The main frame of the Remington electric typewriter includes a top plate 1 supported by corner posts 2 from a base casting 3. The parts of the machine above said casting 3 are much like those of the Remington No. 12

typewriter. A carriage truck 4 runs by roller bearings 8 on stationary rails 10I supported by the top plate 1 inthe m2 nner common inl of the platen frame is a wheel 16 running on y a shift rail 17 which is supported by two upright members 18, which are adjustableas to length, each one being pivoted at 20 to a rock arm 21, the. two rock arms being* fast on a rock shaft 22 mounted in bearings on the base casting 3. One of these arms 21 is operated by the power mechanism, as will be described hereinafter. f

In the base casting 3 of the Remington electric typewriter there are mounted the key mechanismv and the devices controlled thereby and there is also mounted a power roller lili ' left-hand portion of 23 whose shaft 24 is journaled in the side plates of the base casting 3. This power roller is continuously driven in the-direction of the arrow in Fig. l by an electric motor, not

l shown.

ent instance surrounded by spacing bushings 30. Said casting 25 comprises a base portion, as will be seen from the drawings, and rising from the forward end thereof are two upright portions 3l and 32, and from the rear end of said base portion there rises a somewhat taller upright portion 33. The uprights or brackets 3l and 32 are spaced apart as viewed in Fig. 6, and through holes therein there passes a bearing pin or shaft 34 on which is journaled a gear wheel 35 which meshes with a gear wheel 36 mounted for the purposev on the end of the power roller 23. Said power roller and the gear 36 may be considered for the purposes of this case as a conventional illustration of any suitable source of power.

A cani or eccentric disk 37 is also mounted onthe bearing pin or shaft 34 6) said disk having an elongated hub 38 which is mounted rotatably on the pin 34 and which in turn takes a bearing inside of the perforation in the upright bracket 32. The cam 37 may be variously shaped, but in the present instance it is of circular outline. The the pin 34 is made the full size of the opening in the bracket 3l, the balance of said pin or shaft being of reduced diameter as shown. Tmmediately at the left of the cani 37 there is journaled on the shaft 34 a ratchet wheel 40, 5, which is rigidly secured to the gear wheel 35. Tn the present instance said ratchet wheel has a hub projecting' leftward therefrom and screwed into the gear. The shaft 34 may be retained in place by any suitable means. As shown, it has a wide-headed screw 39 screwed into its righthand end overlapping the surface of the casting 25, tol prevent movement of said shaft leftward. Motion of its rightward is prevented by the enlarged left-hand end of the shaft contacting with the hub of the ratchet wheel 40. l

The ratchet wheel 40 is an element of a clutch, another element of which consists of a pawl 41 pivoted on a stud 42 projecting from the earn 37. This pawl has a tail which is adapted to contact with a second stud 43 alsc projecting from the cam disk 37 to limit the motion the pawl out of engagement with the ratchet wheel. Said pawl has an arm or ear 44 projecting radially therefrom into the path of a hook-like dog or escapement lever 45, the hub 46 of which, Fig. 7,

reenter is pivoted to the upright 33. Tn the present instance an enlarged part of the screw 26 serves as a pivot for this lever as shown in Fig. 7.

The escapement dog has an upright arm 47 which is connected by a push link 48 with an arm 50 depending from a transverse rock shaft 51 in the keyboard part of the base casting 3. @On the left-hand side of the machine shown in Fig. l, a lever 52 projecting forward from the arm 50 carries a case shift key 53. Tivoted at 54 to the lever 52 is a shift lock key 55 consisting of a button on the uper end of a lever which at its lower end has aihook 56 adapted to engage under a projecting flange 57 of a bracket 53 which is secured to the side wall of the casting 3. The key or lever 55 is controlled by a spring 60. The case shift lever 52 in common with the other key levers in the machine is guided at its forward end in a comb plate 61. The purpose of the rock sha-ft 51 is to enable another case shift key to be connected with said shaft on the right-hand side of the keyboard. The construction is such that when the case shift key 53 is depressed the escapement dog 45 is raisedto the position shown in dotted lines in Fig. 5 and if the shift lock key 55 be operated this dog will remain in that position as long as the shift key is locked down.

its best shown in Fig. 5 a @-spring 62 connected to the pawl 4l and to a stud k63 projecting from the cam 37, tends to pull the hooked end of the pawl into engagement with the ratchet 40, which when it is done constitutes the closing of the clutch. This will occur when the escapement dog 45 is raised to the dotted line position in Fig. 5 by the depression of the case shift key, whereupon the cam will make a half rotation. Tt will be arrested at the end of such half rotation by a second escapement dog 64 pivoted at 65 in the casting 25. The dog 64 is connected with the dog 45 by a link 59 and the latter dog is acted on by a spring 69 tending to hold it in its ylower position. The whole construction is such that the dogs both normally occupy the lower positions shown in lig. 5 and they will both be elevated when the case shift key is dei pressed, 'the upper dog 45 releasing the ear 44 of the pawl 4l, and the lower dog 64 moving to the dotted line position of lig. 5 where it will arrest the pawl 4l and stop the rotation of the cani 37 halfway. lWhen the case shift key is released the spring 62 restores the dogs 45 and 64 to normal position with the effect 'that when the dog' 64 moves downward it releases the pawl 4l to the action of the spring 62, which closes the clutch until the rotation ofthe cani is completed, will be arrested and the clutch opened by the upper dog 45..

When the are in the normal position the spring 62, acting on the pawl 4l andthe latter reacting on the whereupon pawl 4l dog 45, tends to more 1.

lll@

the cam 37 'in reverse direction, and if means were not provided to prevent 1t, it would so move said pawl and cam, with the result that the pawl 41 would be continually rattled back and forth by the teeth of the ratchet 40. ln order to prevent this, various means may be provided. That shown in the drawings includes a disk 66 fa-stened to one side of the cam or eccentric 37and made with two oppositely disposed shoulders 67. One of these is normally engaged by the inclined hook-like end ofl a detent or arm 68 mounted on a rock shaft 70 suitably pivoted in the casting 25. rlhe arm 68 has a pin 71 projecting therefrom and acted on by a spring 72 which pulls the nose of the arm 68 against the periphery of the disk 66 and which normally presses the inclined hook-like part of said arm aga-inst one of the shoulders 67 of said disk. The angles of said shoulders 67 and of the hook-like part of the arm 68 are so designed that they amount to a bevel, the shoulder 67 reaching the point or arm 68 just before the pawl 41 becomes disconnected from the ratchet 40 by the opening of the clutch. The spring 72 draws the inclined end of the arm 68 against the shoulder 67, completing if necessary the partial rotation of the cam disk and locking it against backward rotation due to the spring 62. rlhe periphery of the disk 66 between the two shoulders 67 is suitably sloped as shown. p

The follower for the cam 37 consists of a wheel or roller 73 journaled on a stud 74 projecting from a lever arm 75 which is pivoted on a pivot screw 76 screwed into the lower part of the casting 25, vsaid screw having its .enlarged bearing part passingv through an elongated hub 77 of the arm 75. ln order to facilitate an assembly of the parts and at the same time to prevent the roller 73 from falling od of the end of the stud 74, said follower wheel is made with a ange over the face of the cam 37, as shown in Fig. 4. When the operating unit is out of the machlne, this roller can be easily removed by simply forcing the lever 75 rearward and all lowing the roller to drop off' the stud.

At its upper end the lever 75 has pivoted thereto at 80 a link 81 which is pivoted at 82 to a branch 83 of a toggle arm 84, which toggle arm is pivoted in the lower rear part of the casting 25 on the same pivot pin or shaft 65 as the dog 64 above described. The shaft 65 passes through suitable holes, one in the vlower part of the upright bracket 33 `and the other in a smaller bracket or lug 85 of the casting 25, said lug or bracket 85 spaced away from the upright 33 by a Vertical cutout 86 (Fig. 5). To facilitate assembling and disassembling of the parts this shaft 65 is simply thrust through the casting and preventedfrom falling out by means of two cotter pins 87. The dog 64 has a hub 88 m'ounted on the shaft 65 and by the side of 78 which laps said hub is the hub 90 of the lower link of the toggle. This toggle link for the sake of stiffness is made of two parallel arms 84 and 91, as best shown in Fig. 7. These two arms are connected together at their upper ends by a shouldered and headed rivet 92, which spaces the two arms apart to a suitable extent to serve as a pivot for the upper link 93 of the toggle, which link is pivoted between the two parts 84 and 91 of the lower link, its upper end being pivoted at 94 to one of the arms 21. rll`he link 81 also passes through the space between the two parts 84 and 91 as shown in Fig. 7, said link being made in semi-circular form, as shown in Fig. 3, so that it can pass -from its forward pivot 80 underneath the pivot 92 to its rear pivot 82.

, connection 84, 91, 93 causes the first part of the upward motion of the platen to be accelerated more rapidly, and the latter part of the motion to be slower, than in a simple harmonic motion, the very last part being comparatively quite slow, so that the platen frame strikes the stops 95 with no objectionable jar. At the same time, the toggle presses said frame firmly against said stops. On the return mot-ion, the platen falls chieHy byl gravity, the conditions being the same as in hand operation, and the fact that the accelerations are then the reverse of those on the up-stroke is not obi jectionable.

Vhen the platen frame is raised to upper case position it is arrested by each hub of the platen striking an adjustable stop screw 95 in the truck 4; and as the power mechanism acts positively it is desirable to introduce an elastic element into the train of connection.

rIhat shown in the drawings is of a design which has heretofore been used for a similar purpose in the Remington electric machine. Each of the arms 21 is made in two parts having an arm 96 pivoted at 97 to the end of the main portion of the arm 21. The latter has a finger 98 projecting therefrom and surrounded by a spring 100. rlhe arm 96 has branches 101 which embrace the finger 98 and the spring 100 is kept under initial stress being compressed between the said arms 101 and the end of the main arm 21. This initial stress is `maintained by a branch 102 of the arm 96 engaging an ear 103 bent off from the main portion of the arm 2l and acting as a stop. The spring/cannot expand any fur'- Y the cam results in ther on account ot this stop but it can loe compressed in case the platen is arrested before the power device has quite completed its motion. The upright 18 is, as usual, made adjustable as to length as indicated at 104k.

Various changes may be made in the details of construction and arrangement without dearting trom my invention.

What l claim as new and desire to secure by Letters Patent, is

l. ln case shift mechanism, the combination with a part to he shifted, oit a continuously rotating driver, a cam, a clutch adapted to connect said cam intermittently with said driver, a case shift key, means controlled hy said key for closing said clutch during a partial operation of said cam and then opening the clutch hy the downstroke of the key and for closing` the clutch during the completion of the operation oi the cam and opening it at the end or1 such operation by the up stroke of the key, and means whereby the rst partial operation ot' the cam shifts said part and whereby the second partial operation ont the cam results in the restoration of said part.

:2. ln case shift mechanism, the combination with'a part to he shifted, of a continuously rotating` power driven ratchet wheel; a cam; a pawl connected with said cam and adapted to engage said ratchet wheel to drive the cani; a case shift key; an escapement controlled hy said key and including twodogs, one dog normally holding said pawl out of engagement with said ratchet wheel and releasing` it on the down stroke of the key, and the other dog on the down stroke ot the key arresting said pawl after a partial operation ot said cam and on the up stroke of the key releasing said pawl to allow the cam to complete its operation; and means whereby the first part of the operation ot the cam shifts said part and the last part of the operation of I the restoration of said part.

Signed at the borough ot Manhattan, city of New York. in the county of New York and State of New York this 23rd day ot December,

it.. D. 1927.

FREDERlCl A. HART.,

Learner 

